New Energy Congress member comments

Ground wind speeds not practical

The increase in power derived from a wind turbine is a function of a cube (to the third power) of the increase in wind speed. Low wind contains very little power. High wind contains proportionately much more. That is why conventional turbines are situated high and in regions with a history of high wind. The wind speed next to the ground, especially in urban settings, is usually very low.

Yes, all factors the same, a "wind tree" might be less expensive over time than a conventional bladed wind turbine. However, all factors are not the same. This application is being proposed for urban settings, where wind speeds are inadequate, and hence where a traditional turbine would not be practical. So what you will end up with is a very expensive power generator that normally puts out very little power, with a few exceptions during wind storms.

The initial market for this technology will need to be urban settings that have higher average wind speeds, but where zoning laws prohibit wind turbines. Once economies of scale kick in, with improvements in material science, then the price might drop to make the technology suitable to less windy areas but it will probably never be feasible for the majority of residential settings due to inadequate wind.

'Rick Dickson wrote on 9/17/07:'

: Sterling's comments have some merit. There are drawbacks to the invention, but the technology, when properly matured, could be a valuable addition to generating electrical power from wind energy. It opens up entirely over-looked regions with lower wind velocities and could ultimately be a valuable addition for the homeowner seeking to lower his electricity costs.

: The piezoelectric textile technology is improving constantly. Newer ceramic textiles generate more powerful voltages. Still we are talking only small voltages for each piezoelectric "leaf" but together, in series, they can produce significant amounts of power.

: Piezoelectric textiles do not need high wind velocities to generate electricity, nor do they require expensive maintenance, like a mechanical wind turbine. These are the two greatest advantages and life cycle costs are cheaper as a result over conventional wind turbines.

: Finally, there is the environmental impact to be considered. Conventional "wind farms" are considered "eyesores" by many people and most communities don't want them. Here in Oregon, they are mostly sited in the remote areas of the Columbia Gorge but even there, they face resistance from local residents. The problem is not just one of aesthetics. They are also very noisy and can kill migrating birds.

: Unfortunately, we need them for now. However, I consider "wind tree" technology to be the next generation of wind technology with many future advantages: aesthetically pleasing (designed to bio-mimic real trees), quiet, low maintenance costs, and completely safe. Best of all, the average homeowner could have one in his/her backyard, providing power to the local grid, and reducing the homeowner's utility costs.

Integrate randomness for good aesthetics

Try to avoid having your "trees" looking like those cell towers that presume to look like trees, but their perfect symmetry makes them totally unconvincing. Use random lengths and angles, within certain parameters, so that the tree actually looks like a tree. No two trees look alike, which is one of their characteristics.

On Oct. 5, 2007, Rick Dickson wrote:

Sterling has an excellent point there. A potential "wind tree"

forest would be more aesthetic-looking, if the "wind trees" were

constructed of material cut at random lenghts and angles. Interestingly, a "wind tree" forest might also provide some of the functions of a real forest as well: habitat for birds, squirrels, and other small animals, as well as the important forest cover function of reducing soil runoff and cooling the ground temperature.

Once the material science of piezoelectric textiles advances enough, I am sure "wind tree" and "kelp tree" technology will increasingly advance to the point that they will become significant players in the renewable energy device market.

"On Oct. 6, 2007, Rick Dickson wrote:"

Sterling's initial comment about the formula for computing wind power does not apply to piezoelectric textile systems. The formula applies only to a mechanical wind generator system, which the "Wind Tree" concept is not. Piezoelectric textiles can be activated by much

lower wind velocities, albeit at lower individual voltages. The same can be said for the "Kelp Tree" concept...simple ocean swells and tidal action would be enough to bend the "Kelp Tree" leaves and generate consistent electrical power.

"On Feb. 9, 2008, Rick Dickson wrote:"

I have been interviewed by a film producer, who is making a movie for the Discovery Channel about renewable energy devices. The producer was interested in the Wind Tree, Kelp Tree, and piezoelectric roadbed concepts, so I hope to see them publicized soon. It appears that the piezoelectric Kelp Tree has the potential for the most immediate development, as it can generate considerable quantities of electrical power nearshore, while providing critical ocean fauna habitat. There are no negative environmental consequences to any of the piezoelectric technologies discussed above, other than those related to manufacture of the piezoelectric materials themselves. The problem remains one of economics. The technology is feasible, simple, and cheap over the long-term but the cost per kilowatt hour is still prohibitive in the short-term compared with conventional renewable energy technologies. Since life-cycle costing is not always considered, piezoelectric large scale power generation schemes tend to fall out of consideration. However, when total life-cycle costs, including repairs and maintenance are considered, piezoelectrics are more competitive, but currently still more expensive than more conventional technologies. However, if total costs and benefits to the environment were considered, these devices might be considered more practical for implementation. I plan on testing a very small scale piezoelectric Kelp Tree bed experiment on the Oregon coast this summer and hopefully collect some useful data.